Martin Frobisher, the route managing director for Network Rail, said: “A train hit a landslip, caused by torrential rain, resulting in a small section of the train to leave the tracks a few miles north of Watford. The train remained upright and there are no reported passenger injuries.

“Engineers are on site and train services are now running through the area but it will be some time before a normal timetable resumes.

“Our priority is to fully reopen the railway as soon as it is safe to do so. A full investigation into what happened will take place.”

Bad UK weather 2016

Forecasters predict torrential rain, hail showers and thunder storms across most of the country on Tuesday - putting a dramatic halt to the recent warm spell/